Recent investigations Of children with Attention Deficit/Hyperactivity Disorder (ADHD) have demonstrated neuropsychological deficits using a variety of neuropsychological tests. Since many of the tests which have demonstrated ADHD-related deficits assess putative frontal-lobe functions, many investigators have suggested a frontal lobe dysfunction in ADHD children. Similar frontal lobe deficits on neuropsychological tests have not been investigated in adult patients with ADHD. Similarities and discrepancies in results across populations may increase our knowledge concerning the developmental nature of this disorder. Further, similar results across populations could provide Convergent validation of previous findings in children. Thirty adult ADHD clinic patients, 30 adult anxiety- disordered clinic patients, and 30 normal comparison subjects will complete a brief neuropsychological testing battery designed to assess multiple frontal lobe functions. Tests include the Continuous Performance Test as a measure of sustained attention and inhibition/impulsivity, the Rey-Osterrieth Complex Figure Task as a measure of planning and organization of output, and the Posner Visual Orienting Task which assesses multiple aspects of cognitive flexibility including the ability to shift attention. Between-group comparisons will evaluate performance on neuropsychological test outcomes. Interpretation will involve comparing results across the tests and comparing results of this study to similar studies conducted with ADHD children.